Although there has been substantial work documenting behavioral change in spatial cognitive processing, little is known about the development of the neural systems that mediate these functions. Recent advances in fMRI now make it possible to ask critical questions concerning the relations between behavioral change and change in the associated brain systems: What does it mean to say that particular brain regions mediate, or to come to mediate, certain types of processing? How do patterns of neural commitment emerge in development? Specifically, to what extent does the development of the neural systems reflect the profiles of change observed in behavioral data? The major goals of this proposal focus on documenting the relationship between developmental change in a basic aspect of spatial cognitive functioning, visual pattern processing, and change in the brain system, the ventral occipital temporal lobe system, that mediates these functions. Three series of studies are proposed. The first is focuses on mapping developmental change in the functional organization of the ventral visual system, exploring the neural organization of category specific information along the ventral surface of the temporal lobe. The second is directed toward examining change in the patterns of hemispheric lateralization for the basic cognitive processes involved in spatial pattern analysis, focusing on the separable process of configural, or global, and featural, or local, level processing. Third examines regulation of information exchange across the cerebral hemispheres, looking at the exchange of information related to global and local level processes. In addition, because all of these studies use functional Magnetic Resonance Imaging (fMRI) to address questions of brain organization in pediatric populations, this project will also investigate two methodological questions: (1) Are there changes with development in the BOLD response. Arterial spin labeling (ASL) measures will be employed to address this question; (2) Are there age-related change in brain morphology as it relates to anatomical normalization?